/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    https://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.grails.datastore.gorm.neo4j;

import java.io.Serializable;

/**
 * An interface for generating unique identifiers for instances
 *
 * @author Stefan
 * @author Graeme Rocher
 */
public interface IdGenerator {
    /**
     * Default id generator types
     */
    enum Type {
        /**
         * Native identifiers using the Node id
         */
        NATIVE,
        /**
         * Assigned identifiers, assigned by the developer
         */
        ASSIGNED,
        /**
         * Identifiers generated using the Snowflake algorithm
         */
        SNOWFLAKE,
        /**
         * Custom generator
         */
        CUSTOM
    }

    /**
     * @return Generate and return the next identifier
     */
    Serializable nextId();

}
